Several US military bases in Europe have been placed on high alert over the weekend due to a potential terrorist attack targeting American personnel, according to multiple reports. This heightened state of alarm, known as Force Protection Condition "Charlie," is the second highest level issued by the US Army and has not been witnessed in at least a decade, officials said.

The US Army garrison in Stuttgart, Germany, which houses the US European Command headquarters, was among the bases that raised their alert status to "Charlie" on Sunday. The condition is activated when an incident occurs or intelligence suggests the likelihood of terrorist actions or targeting against personnel or facilities.

While officials at the US European Command did not provide specific details about the reason for the heightened alert, they stated that they are continuously assessing various security factors and are remaining vigilant. This increased state of alert has not been seen for at least 10 years, indicating a serious and reliable threat, according to a US official stationed at a base in Europe.

In addition to facilities in Germany, American military bases in Italy, Romania, and Bulgaria have also been placed on high alert, as reported by the independent military publication Stars and Stripes. European authorities have been particularly cautious during the ongoing European football championships in Germany, deploying 580 international police officers to assist with security.

The heightened security measures are not limited to the football championships. France has issued warnings of potential attacks during the upcoming Paris Summer Olympics, which are scheduled to begin on July 26. In May, an 18-year-old Chechen man was charged with plotting to target spectators attending soccer games during the Olympic Games, expressing a desire to become a martyr.

As the authorities remain focused on ensuring the safety of personnel and visitors, additional security measures are being implemented. The US military bases in Europe are working diligently to minimize any potential risks during these times of increased vigilance.